Valve-grinding tool.



W. H. PEARCE.

VALVE GRINDING TOOL.

APPLICATION FILED our. s, m13.

Patented Mar. 16, 1915.

NITED STATES PATENT OFFICE.

WALTE HENRY PEARCE, OF SUIYIIMIT, NEW JERSEY.

VALVE-GRINDING TOOL.

Specification o! Letters Patent.

Application led October 3, 1913. Serial No. 793,182.

l u (mw/10m it may concern:

Be it known that I, IVALTER HENRY PEARCE, a citizen of the United States, residing at Summit, county of Union, and State of New Jersey, have invented certain new and useful Improvements in Valve- Grinding Tools, of which the following, taken in connection with the accompanying sheet of drawings, is a full, clear, and concise description'.

My present invention more specifically comprehends an automatic valve grinding tool of the screw driver type provided with means for regulating the degree or extent of rotation, which the tool may impart to the valve upon its seat in order-to prevent the formation of grooves or pits on either the valve or its seat by the abrasive material employed in the grinding process. In order to accomplish this result the extent of rotary movement imparted to the tooland the valve during the eifective operating movement of the tool is less than a circle or comlete revolution. I accomplish this result y a combination of cooperating parts which produce a regularized differential movement in opposite directions of rotations of the tool. Each alternative movement of the tool that is movements in the same direction being uniform in extent but the successive movements in opposite direction varying in degree, the lesser of the two. Both movements are caused by the reciprocation of a hand grip and associated parts along the spirally groovedy body of the tool. The object of ,regulating the extent of active valve grindto less than a complete circleI ing movement or revolution is as explainedto prevent the formation of minute circular grooves or of pits in the valve or its seat by the abrasive compound which frequently occur during ordinary grinding processes as now practised with known tools. It will be apparent that by imparting to the valve a' partial rotation such an objectionable condition cannot result, because the initial point at which the abrasive action begins and the point at which it ends on"each active rotation of the tool are separated, leaving an intermediate zone which' cannot be traversed by abrasive grit, which through adhesion to the valve may be carried by it.

-To the accomplishment of this desirable funttion my tool has been designed and it essentially comprises a means whereby the the active grinding movement being reciprocating hand grip is so formed as to Patented Mar. 1 6, 1915. Y

`provide for a degree of lost motion on its active or downward stroke, which imparts to the tool the partial working'rotation referred to, while on the inactive or upward stroke no lost motion occurs and the tool is made to rotate in the reverse direction slightly beyond a complete circle or full rotation. Thus nthe active working movements while causing a grinding or abrasiv action between ltliretLre Walve upon its seat, prevents any abraslveg'lit from traveling from that zone of contact represented in a circle by the extent or degree of rotary movement of the tool into that zcne or segment of the circle represented by the difference between the initial starting and finishing points in the movement of the tool.

In the drawings accompanying this specification I have shown a preferable embodiment of my invention, said form being illustrated rather than definitive, since modifications and changes might easily be made or resorted to departing from the spirit of the invention.

Figure l illustrates the tool in practical operation associated with a valve of a gas engine, so much of the latter being shown as will serve to aforda complete understanding of the construction and operation of the tool. Fig. 2 is a fragmentary detail of the reciprocating hand grip illustrating the lost motionl mechanism. Fig. v3 is a sectional view thereof taken on lines A-A of Fig. 1V

together with a diagrammatic chart4 illustrating the progressively shifting points of inauguration and termins of the grinding or alternateV working movements of the tool. Fig. .4 is a fragmentary detail partlv in section illustrating a modification including a` detail spring arrangement for providing 3against free reverse rotation of the lost motion guide sleeve, and Fig. 5 is a cross-sectional view taken on line B-B of Fig. 4.

In detail the tool consists of a conventional screw driver consisting of a shank portion 1, rovided at its lower extremity with an en arged flattened end 2 and at its upper end the hand grip or knob 3. The valve engaging end 2 and the shank portion l being made separable parts suitably fastened together as shown ,and in working unison whi e the hand grip 3 is permitted to remain stationary under the grip of the user while 'the active workingy parts of the vtool moves, The shank 1 is provided with called automatic screw driver which is wellknown in the. art. Tor this conventional form of screw driver I have applied my lost 1notion reciprocal hand grip which while oper- `atin 1r in the same manner as reci rocal hand gripsof the described well-known screwdriver type, imparts the described movements Vto obtain the desirable results heretofore pointed out. This reciprocating hand grip when' made in accordance with my invention and when embodied in the specific illustrated form shown consistsin providing the sleeve 6 or an independent segmental sleeve 7 fast thereto with two series of oppositely disposed sei-rations of sawigooth formation, the teeth S of one se ries being disposed at a different angle or incline to the teeth 9 of the opposite series` said teeth S and 9 being substantially at right angles to each other, but separated and terminating in staggered relation. Each tooth of each series has an angular f guide face 10 and a rectilinear guide face 1l, the latter being parallel to the axis of the tool and in line with the center of the angular guide face 10 ofa tooth of thc opposite series. this for the purpose of guid- `ing the guide pin 12 carried by the sleeve 13. The sleeve 13 serves as a hand grip for the operator of this described mechanism which constitutes the lost motion mechanism wherehv the differential rotary move ments are attained.

In the. illustrated embodiment, I have provided two series of six teeth each and the tool in operating on what I have termed its working stroke, that is the effective grinding stroke. thel guide pin 12 is caused to move.. as will be explained more full)1 later..t`rom its upper position in engagement with the teeth ofthe upper segment of the lost motion sleeve 7 as indicated at 14 to the. lower position as indicated at 15 in a path indicated in Fig. 2. In this' downward movement the pin 12 engages the angular or incline guidev face 10 of a lower tooth imparting thereto a partial rotary movement. this movement being imparted to the sleeve (3a causes the pins or projections 5 and 6 to move along the groove 4 of the shank without rotating the latter. This constitutes lost motion in the operation of the device. Vhile the segmental sleevel 7 is provided with six uniform teeth. more or less teeth may be emploved and the degree of rotation of the tool correspondingli.y regulated. 'The sleeves 6, 7 and 13' all move together when the pin 12 engages the low partbetween the teeth of the lower The l above is descriptive of a conventional sosegment causing the pins 5 and 6 to travel along the remainingr portion of the groove 4 rotating the shank 1 accordingly. 'hen the reciprocating hand grip is moved upwardly'along tie shank, no` lost motion takes place but rather a greater degree of rotation is imparted to the tool end, as will presently be explained.

In" order to cause the pin 12 during the operation of the. tool to progressively travel from between alternate teeth of the two segments of the segmental sleeve 7 in oneA 4direction and to prevent an independent free movement or rotation of the sleeve 7 and sleeve 13, when the guide pin 12 is in a neutral position between thel series of teeth as indicated by the line C-C of Fig. 2, in an opposite direction I provide within the lower extremity of the sleeve 13 a spring 1G which frictionallv bears against the lower segment of the sleeve 7, the surface of which is provided with indentations 17 into which the end of spring. by reason of its inherenttension snaps confining the sleeve 7 to a relative movement in the direction of the arrow (see Fig. 5). The pin isv therefore forced to travel 'the path indicated in Fig. 2.

The operation of the tool is substantially as follows: The hand of the operator-grasp- -in engagement with the serrated upper segment of the sleeve 7 (which position is indicatcd at 11 in Fig. 2) downwardly into engagement with the incline surface 10 of a tooth of the lower segment. Continuons movement. of the sleeve 13 will canse the pin 12 to partially rotate the segmental sleeve 7 until the pin 12 reaches the lower end of the incline and abnts the wall of an adjacent tooth. This partial rotary movement is, of course. transmitted to the guide pins 5 and 6 which travel in the groove 4 of thel tool shank without rotating the latter.' Owing to the fact. that the series of teeth are in staggered relation and are six in number in each series` the pin rotates ,the sleeves 6 and 7. one twelfth ot the circumference ot the 'ShankA 1, of the tool without causing it to rotate. Continued movement Vot'thc sleeve 13 along the shank eausil thesegmental sleeve 7 to move downwardly with it in rec-- tlincar direction the "einaining eleven twelt'ths of the rcmaii ing or nntraversed portion of the shank. Assuming that the flattened end of the screw driver is inxthe the limiting stop m.

initial position indicated atv win the dia Agraiiimatic illustration Fig. 3, downward movement of the sleeves 13 and 7 will cause the valve torotate until the sleeve 7 abuts The position then-of the atteiied'end 2 of the tool and the slot in the valve 'at the end of this stroke is at b (see Fig. 3) In this manner, the valve has beenlrotated on its seat 'eleven twelfths of a 'complete 'revolution On the' upward inactivastroke .or 4reciprocable movement of the gripping sleeve. 13 and its associated parts,no 10st motion occurs. A -In this gtroke the pin112 will move from its lower position indicated'at'l (Fig. 2) and abut the incline of annp'per toothri Continued movement will causethe sleeves'and 7,'

carrying pins' 5. and 6 to traverse theen- Y tire length of the-'shank'nntil the limiting stoplm. is reached, causing a complete `revo- V.lation otV the tool eifd 2..v Continued up ward pressure' will cause the pin 12 bear- .ing against the inclinelO to .partially rotate the sleeves 6* in reverse direction which in turn through-pins 5 and. 6v causes the tool to move with itthus rotating the tool a one twelfth. degree beyond the complete circle, the 'valve Ain Athis movement being disenga'ged-from itsseatunder the action of a springcy'which liftsthe valve when vpressure is 'removed from the tool, (the valve assuming the positicn'shownvin dotted lines in Fig. 1)..' Asexplaifned, no lost motion takes place intliisiiipwardmevement of the sleeve 18,-.the'p'ins 5..a`n`d'.6 beingl forced to travelv the entire length ofthe grooves 4 and then the sleeves 6 and 7- causing it to rotate slightly further to transcribe more than a complete revolution inta' reverse direction, as indicated in the diagram, the travel of the flattened end 2 of the tool andthe' slot inthe valve'bei'ng indicated from b to c. The Anext ,succeeding downward movement of the sleeveand associated parts in which movement the los't motion described again occurs will cause the tool and valve to rotate to the position indicated at d. Thus it will be seen that the working rotary movements of the valve upon its seat arev partial rotations; in no instance a complete revolution thus resulting in perfect grinding and producing highly finished surfaces on valve and'seat.,-

Having thus described my invention what I claim as new herein and desire to secure by` I Letters Patent '-is:

1. A valve grinding'tool comprising a spirally-groovcd shank, a valve-engaging end' and .reciprmtating means coperating with the grooved shank and adapted to im- ,Jartto the valve-engaging end regularized .iir'erentialfpppoSite rotary movements.

2. A"val,iie'gi'iiiding tool comprising a spirally-groved shank, a valve-engaging end and reciprocating` lost motion means handle, and at its opposite end with a tool,

adapted to cooperate with a valve ground, reciprocating means coperating with the 'grooved' shank for operating the-l tool, said reciprocating means,being provided with a lost motion mechanism, where by the reciprocating member may be moved 21 O ng the grooved shank a predetermined -v distance in one direction before being .brought into eiective working position, so as to impart thereto partial rotary movement, said 'member adapted when moved rectilin- -early in the opposite direction to impart a greater rotary movement to the tool in -re. versed direction. f j

5. Inatool of the character described, a grooved'shank, having at one end atool and at its opposite end a handle, a reciprocating member including lost motion mechanismv associated with the shank aiidoperabl adapte to coperate with the groove thereof, to impart relatively diferentdegrees of rotary movement to the tool upon the reciprocal movement of said member from one end of the shank to the other.'

6. Inl a tool of the character described, a v

grooved shank provided ,with a tool-eiid and a handle end, a reciprocating member cooperably associated with the groove ofsaid shank, said reciprocating member being provided with a lost motion mechanism, whereby movement of said reciprocating'member along the shank in one direction will impart to the tool, a predetermined rotary' movement. and movement in the opposite di-' rection will impart to said tool arelatively different predetermined rotaryl movement in a reverse direction. ,l

7. In a tool of the character described, a

spirally grooved shank, a tool end fixedly connected therewith atione en'd, a handle mounted at the opposite end and: independently` movable thereof, a reciprocating lost motion device mounted upon the shank in operable association with the spiral groove thereof, said reciprocating device adapted to ,impart differential degrees of rotation to the tool end, sequentially-in alternate directions.

S. A tool of th'e character described;l comipc iio

prising a spirally grooved shank, an operatv ing tool end, a relatively movable handle tion.

portion, and limitingstops adjacent its ends, a reciprocating member provided `with lost motion mechanism opel-ably associated with the grooved shank, said reciprocating member adapted on its full downward movement to impart a predetermined deg-ree of rotation to the tool end and upon its full upward movement to impart a greater predetermined degree of rotation in reverse direc- 9. Atool of the characterrdescribed,^com

prising a grooved'shank portion provided' -with' a relatively movable handle, a fixed tool end, a reciprocating member operably' associated with the shank, and limiting stops on the'shank for' limiting the movement of the reciprocating member, said reciprocatirg member comprising'a sleeve provided with a 4'pin or projection operating in the groove of the shanlrand a circumferential cutout portion, -a hand grip or sleeve provided with a pin or projection operating in the cutout portion of the first-mentioned sleeve, said pin adapted to coperate with and impart to saidsleeve a relatively small degree of rotation, upon the rectilinear movement of the -hand grip or sleeve-along the shank, whereby differential rotary movements may be imparted to the tool end.

` 10. A` tool of the character described, comprising a grooved shank, a reciprocating member cooperating therewith adapted to impart rotary movement thereto, said reciprocating member being provided with a lost motion mechanism, comprising inner and outer sleeves, the inner sleeve operably engaging the grooved shank and provided with two series of teeth in staggered relation, one series of teeth being at right angles i -ber along the shank in one direction whereby a definite predetermined rotary movement is imparted tothe tool end, said mechanism loperating when moved in reverse direction to impart to said toolend -a greater predetermined rotary movement in reverse direction.

In witness whereof I have hereunto ser my hand in the presence of two subscribing witnesses. l.

VALTER HENRY PEARCE. Vitnesses: \V. P. HAMMOND, P. FRANK SONNEK. 

